2. Salivary Gland Diseases

4. The salivary glands consist of 3 paired major glands,
1- parotid glands: opens against the upper 2nd molar buccally by Stensen’s duct, the secretion is mainly serous.
2- submandibular glands: opens near the lingual frenum by Warthin’s duct, the secretion is mixed but mainly serous.
3- sublingual glands: open near the opening of submandibular gland by Bartholin’s duct, the secretion is mixed but mainly mucous.
In addition to these major glands, there is a countless of minor salivary glands found in almost every part of the oral cavity, except the gingiva & anterior region of the hard palate.
Both, major & minor salivary glands consist of parenchyma elements which are supported by C.T. stroma.
The paranchymal is derived from the oral epith & consist of terminal secretory units leading to ducts that open into the oral cavity. The parenchyma surrounded by a C.T. capsule & extend into it.
The blood & lymphatic vessels & nerves that supply the gland will contained within the C.T.
The normal function & health of the mouth depends on the normal composition & secretion of the saliva.
The important function of salivary glands is the production of saliva which contain various organic & inorganic substances & help in mastication, deglutition & digestion of food.

5. Investigations for salivary glands:
1- Sialometery: measures the amount of saliva production in a certain time.
2- Sialochemistry: measures the composition of saliva.
3- Sialography: by introducing the iodine containing contrast media through the opening of the duct.
4- Sonagraphy: Ultrasonic patterns when dealing with minor salivary glands.
5- Cytology: by aspiration.
6- Biopsy.
Classification of salivary glands diseases:
1- Obstructions: this could be by calculi or cystic type (stone, mucocele)
2- Infections: viral (Mumps), bacterial (acute & chronic Sialadenitis)
3- Degenerative changes: Sjogren syndrome, radiation.
4- Functional disorders.
5- Neoplasms.

6. 1- Obstructions: duct obstruction may result from either: A- blockage of the lumen (calculi, mucocele) B- disease in or around the duct wall (fibrosis, neoplasia)
A- Sialoliths (S.G. stone):
Mean presence of calculi or stones within the duct.
The calculi believed to arise from the deposition of ca ++ salt around a nidus of debris within the duct lumen, these debris include bacteria, ductal epith cells, or foreign bodies.
70-90% of stones occur in the submandibular gland, & this due to long tortuous path of the duct & thick secretion of the gland. about 6% in parotid gland & 2% in sublingual gland & minor S.G.
Mainly occur in adult male & is usually unilateral.
Symptoms: pain, sudden enlargement specially at meal time.
Radiography: there will be radiopaque mass, however, about 40% of parotid & 20% of submandibular stones are not radiopaque, therefore Sialography may be needed to locate them.
Treatment:
removing the calculi by manipulation or incision of the duct.

8. B- Mucocele 1- Mucus extravasation cyst:
A common lesion of the oral mucosa it is of 2 types:
1- Mucus extravasation cyst:
Result from rupture of a S.G. duct & spillage of mucin into the surrounding soft tissue, as a result of local trauma.
Clinically, appear as a bluish or translucent swelling, soft, fluctuant, range from mms to cms. Mostly in child & adult. The lower lip is the most common site usually lateral to the midline.
The duration of the lesion can vary from a few days to several years & many patients relate a history of a recurrent swelling that may periodically rupture & release it’s fluid contents.
Mucus extravasation cyst is not true cyst, because it lacks an epith lining.
Histopathology:
An area of spilled mucin surrounded by a granulation tissue response.
The inflammation includes numerous neutrophils & foamy macrophages.
In some cases, a ruptured salivary duct may be identified feeding into the area.
Treatment: surgical excision.

9. 2- Mucus retention cyst:
This derived from cystic dilatation of a duct, due to partial or complete obstruction of the duct, that make the mucin to remain (retention) within the duct.
Clinically, like the extravasation type.
Histopathology:
Cyst lining is variable (ductal epith in origin) composed of cuboidal, columnar or squamous epith, surrounding the mucoid secretion in the lumen.
Treatment:
Surgical excision.

10. 3- Ranula
it is a type of extravasation mucocele, the source of mucin spillage is usually the sublingual gland or from submandibular duct or possibly from minor S.G. in the floor of the mouth.
Clinically, appear as swelling in the floor of the mouth resemble a Frog’s belly.
It may interfere with the speech or mastication, because it causes pushing of the tongue up toward the palate.
Treatment:
By total or partial removal or marsupulization.

11. 2- Infections A- Viral infection (Mumps):
Is an acute, contagious infection which often occurs in minor epidemics & is caused by Paramyxovirus.
It is the commonest cause of parotid enlargement & may affect the submandibular & sublingual glands.
The virus transmitted by direct contact with infected saliva & by droplet spread. Mostly affect the children & the incubation period is about 2-3 weeks.
Clinically, the disease start with fever, malaise, followed by painful swelling of sudden onset behind the ear.
The bilateral parotid involvement occur in about 70%.
Then the swelling gradually subsides over a period of about 7 days.
Occasionally, in adults other internal organs are involved, such as testes, ovaries, CNS, & pancreas. Orchitis is the most common complication, occurring in about 20% in adult males.
After the attack, immunity is long-standing, & with use of vaccine, childhood mumps becomes infrequent.
B- Pyogenic bacterial infections: are common & may be seen after major abdominal surgery or in glands that have been obstructed.

12. 3- Degenerative disease
Sjogren Syndrome
Is an immune-mediated chronic inflammatory disease, characterized by lymphocytic infiltration & acinar destruction of salivary & lacrimal glands.
Mainly affects middle-aged females, & symptoms related to dryness & soreness of the mouth & eyes are common clinical presentations.
The patient also complain from difficulty in swallowing & speaking, increased fluid intake, disturbance of taste, & rapidly progressive caries.
S.G. enlargement is usually bilateral without pain, & predominantly affects the parotid gland.
The disease classified into 2 types:
1- primary: xerostomia + xerophthalmia
2- secondary: xerostomia + xerophthalmia + C.T. disease usually rheumatoid arthritis.
Histopathology:
Initially, the S.G. show lymphocytic infiltration around intralobular ducts with acinar atrophy & obliteration of the duct lumen by proliferation of ductal epith, lead to formation of islands of epith tissue, termed epimyoepithelial islands.
Finally, the lesion consists of sheets of lymphoid cells surrounding the epimyoepithelial island & replacing entire S.G. lobules.